Goal of this thesis was to develop a tool for visualization of SQL queries. Developed tool can analyze SQL queries and generate a diagram for analyzed query. It supports basic elements of SQL language and some of the advanced elements, such as: updating, grouping and merging of data, invocation of functions in query. Tool was developed on Java SE platform, and JavaFX was used to design graphical user interface. Open source software, Graphviz, was used to visualize generated graph.